SIST EN 13645:2003

2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.NRSHQVNLKAnlagen und Ausrüstung für Flüssigerdgas - Auslegung von landseitigen Anlagen mit einer Lagerkapazität zwischen 5 t und 200 tInstallations et équipements de gaz naturel liquéfié - Conception des installations terrestres d'une capacité de stockage comprise entre 5 t et 200 tInstallations and equipment for liquefied natural gas - Design of onshore installations with a storage capacity between 5 t and 200 t75.200Petroleum products and natural gas handling equipmentICS:Ta slovenski standard je istoveten z:EN 13645:2001SIST EN 13645:2003en01-januar-2003SIST EN 13645:2003SLOVENSKI
STANDARD



SIST EN 13645:2003



EUROPEAN STANDARDNORME EUROPÉENNEEUROPÄISCHE NORMEN 13645December 2001ICS 75.200English versionInstallations and equipment for liquefied natural gas - Design ofonshore installations with a storage capacity between 5 t and200 tInstallations et équipements de gaz naturel liquéfié -Conception des installations terrestres d'une capacité destockage comprise entre 5 t et 200 tAnlagen und Ausrüstung für Flüssigerdgas - Auslegung vonlandseitigen Anlagen mit einer Lagerkapazität zwischen 5 tund 200 tThis European Standard was approved by CEN on 15 November 2001.CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this EuropeanStandard the status of a national standard without any alteration. Up-to-date lists and bibliographical references concerning such nationalstandards may be obtained on application to the Management Centre or to any CEN member.This European Standard exists in three official versions (English, French, German). A version in any other language made by translationunder the responsibility of a CEN member into its own language and notified to the Management Centre has the same status as the officialversions.CEN members are the national standards bodies of Austria, Belgium, Czech Republic, Denmark, Finland, France, Germany, Greece,Iceland, Ireland, Italy, Luxembourg, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland and United Kingdom.EUROPEAN COMMITTEE FOR STANDARDIZATIONCOMITÉ EUROPÉEN DE NORMALISATIONEUROPÄISCHES KOMITEE FÜR NORMUNGManagement Centre: rue de Stassart, 36
B-1050 Brussels© 2001 CENAll rights of exploitation in any form and by any means reservedworldwide for CEN national Members.Ref. No. EN 13645:2001 ESIST EN 13645:2003



EN 13645:2001 (E)2ContentspageForeword.3Introduction.41Scope.52Normative references.53Terms and definitions.64Environmental impact.74.1General.74.2Emission control.74.3Boil-off / flash gas management.74.4External communication networks.85Safety plan.85.1Purpose.85.2Collection of data and information.85.3Threshold values.95.4Identification of risks.105.5Estimation of the consequences of a gas or LNG release.116General safety measures.126.1Leaks and spillage protection.126.2Overpressure protection.136.3Fire protection.136.4Confinement.136.5Emergency shutdown.136.6Commissioning and decommissioning.136.7Inspection.146.8Personnel.147Design of vessels.147.1General.147.2Insulation.147.3Foundations.147.4Instrumentation.157.5Overpressure protection.157.6Impounding basin.167.7LNG transfer.167.8Overflow.167.9Distance between vessels.168Installation design.168.1Hazardous areas and restricted access area.168.2Unloading and loading areas.168.3Circulation and parking.178.4Location of facilities.178.5Lightning and earthing.17Annex A (informative)
Schematic description of a process for a satellite and fuelling plant.18Annex B (informative)
Examples of safety scenarios and calculations.19Annex C (informative)
Examples of LNG storage vessels - Design concepts.25SIST EN 13645:2003



EN 13645:2001 (E)3ForewordThis European Standard has been prepared by Technical Committee CEN/TC 282 "Installation and equipment forLNG", the secretariat of which is held by AFNOR.This European Standard shall be given the status of a national standard, either by publication of an identical text orby endorsement, at the latest by June 2002, and conflicting national standards shall be withdrawn at the latest byJune 2002.According to the CEN/CENELEC Internal Regulations, the national standards organizations of the followingcountries are bound to implement this European Standard: Austria, Belgium, Czech Republic, Denmark, Finland,France, Germany, Greece, Iceland, Ireland, Italy, Luxembourg, Netherlands, Norway, Portugal, Spain, Sweden,Switzerland and the United Kingdom.Annexes A, B and C are informative.SIST EN 13645:2003



EN 13645:2001 (E)4IntroductionThe objective of this standard is to give functional guidelines for LNG facilities with a total storage capacity between5 t and 200 t. It recommends procedures and practices which will result in safe and environmentally acceptabledesign, construction and operation of LNG plants.This standard is not applicable to existing installations, but its application is recommended when majormodifications are considered.SIST EN 13645:2003



EN 13645:2001 (E)51 ScopeThis European Standard specifies requirements for the design and construction of onshore stationary liquefiednatural gas (LNG) installations with a total storage capacity between 5 t and 200 t. This standard is not applicableto liquefaction process facilities based on hydrocarbon refrigerants. Larger installations are treated according toEN 1473:1997.If other dangerous substances are present in the facility, the aforementioned storage capacity thresholds may bereduced.NOTEIt is essential that the designer refer to local regulation to determine the new values.The installations to which this standard is applicable include the following: LNG satellite plants. The LNG may be supplied by road tankers, barge or rail carriers. After storage, LNG isvaporized and sent out to consumers; LNG gas fuelling stations for vehicles.The installation is limited from the gas inlet or the loading LNG area to the gas outlet or the unloading LNG area.Filling systems are not covered here.For the purposes of clause 4 «Environment Impact» and clause 5 «Safety Plan», this standard applies where LNGstorage capacity exceeds the threshold specified in the local regulation. If this value is not available, a threshold of50 t is recommended.It is recalled that, in any case, local regulations prevail.2 Normative referencesThis European Standard incorporates by dated or undated reference, provisions from other publications. Thesenormative references are cited at the appropriate places in the text and the publications are listed hereafter. Fordated references, subsequent amendments to or revisions of any of these publications apply to this EuropeanStandard only when incorporated in it by amendment or revision. For undated references the latest edition of thepublication referred to applies (including amendments).EN 1127-1, Explosive atmospheres- Explosion prevention and protection- Basic concepts and methodology.EN 1160:1996, Installation and equipment for liquefied natural gas - General characteristics of liquified natural gas.EN 1473:1997, Installation and equipment for liquefied natural gas - Design of onshore installations.EN 12066, Installation and equipment for liquefied natural gas - Testing of insulation linings for liquefied natural gasretention bunds.EN 60079-10, Electrical apparatus for explosive gas atmospheres- Part 10: Classification of hazardous areas (IEC60079-10:1995).ENV 1991-2-2, EUROCODE 1 Basis of design and actions on structures - Part 2-2: Actions on structures - Actionson structures exposed to fire.ENV 1992-1-1, EUROCODE 2 Design of concrete structures - Part 1-1: General rules and rules for buildings.ENV 1992-1-2, EUROCODE 2 Design of concrete structures - Part 1-2: General rules - Structural fire design.ENV 1993-1-1, EUROCODE 3 Design of steel structures - Part 1-1: General rules and rules for buildings.ENV 1993-1-2, EUROCODE 3 Design of steel structures - Part 1-2: General rules - Structural fire design.ENV 1994-1-1, EUROCODE 4 Design of composite steel and concrete structures - Part 1-1: General rules andrules for buildings.SIST EN 13645:2003



EN 13645:2001 (E)6ENV 1994-1-2, EUROCODE 4 Design of composite steel and concrete structures - Part 1-2: General rules -Structural fire design (including Technical Corrigendum 1:1995).3 Terms and definitionsFor the purposes of this European Standard, the definitions given in EN 1160:1996 and EN 1473:1997, and thefollowing terms and definitions apply.3.1above ground vesselvessel of which all or part is exposed above ground level3.2boil-off gasgas resulting from evaporation of LNG near its equilibrium state3.3emergency shutdowna system that safely and effectively stops the whole plant or individual units when an incident occurs3.4flash gasgas resulting from sudden evaporation of LNG out of equilibrium condition3.5impounding areaan area defined through the use of dykes or topography at the site for the purpose of containing any accidental spillof LNG3.6LNG gas fuelling stationinstallation including an LNG storage which supplies vehicles with LNG or gas from vaporized LNG3.7loading areaarea where LNG is loaded from storage vessels to transport vessels when the plant supplies LNG3.8local regulationset of rules, laws, national agreements, international conventions which apply to a site3.9operating personnelany person who is authorised to act on the control of the plant, remotely or locallyNOTEIt can include the drivers of LNG carriers who supply the plant with LNG. In the case of fuelling stations for vehicles,drivers of these vehicles are not included unless it is specified in the management plan of the installation.3.10plant or sitearea inside of which public access is unauthorised3.11underground vesselvessel which is completely buried below the general ground level of the facility3.12unloading areaarea where LNG is unloaded from transport vessels to storage vessels when the plant is supplied with LNG3.13validated modelmodel whose effectiveness has been demonstrated by LNG industrial tests through clearly identified proceduresSIST EN 13645:2003



EN 13645:2001 (E)74 Environmental impact4.1 GeneralAn environmental impact study shall be carried out when the LNG storage capacity exceeds the threshold specifiedin the local regulation. If this value is not available, a threshold of 50 t is recommended.The impact study shall take into account any restrictions on the transportation of LNG.All emissions from the plant, that is, solid, liquid (including water), and gaseous (including noxious odours) shall beidentified. Measures shall be implemented to ensure that normal and accidental emissions are harmless topersons, property, animals or vegetation.An effluent management policy shall be established if relevant. The requirements in the handling of any toxicmaterials shall be identified.Any increase in activity caused by operation shall also be assessed and undesirable levels of activities shall beeliminated if possible or minimized and restricted. The following items should be considered: noise levels; vibration levels; night working, effect of lights; gas flaring or venting; warming or cooling of water.NOTEFog may be created locally by atmospheric vaporizers.4.2 Emission controlThe following shall be safely controlled: combustion products from compressor drivers, submerged vaporizers, fired heaters for regeneration; normal or accidental venting of gases; normal or accidental flaring of gases; oily water condensed during dryer regeneration or from machines; in the case of water-cooled equipment, hydrocarbon contamination of this water from leaking exchanger tubes; disposal of waste products (chemicals, waste oil and chlorinated organic compounds); vaporizer water; odorant chemicals.The standard of emissions control shall follow as a minimum specifications set by local regulation.4.3 Boil-off / flash gas managementContinuous flaring or venting shall be avoided.Boil-off gas can be recycled in a liquefaction process or included in the send-out gas to avoid waste gas duringnormal operation.SIST EN 13645:2003



EN 13645:2001 (E)84.4 External communication networksTraffic rates of external roads, railways and waterway networks near the LNG plant shall be identified.5 Safety plan5.1 PurposeLNG installations shall be designed to minimize the risks to property and life outside and inside the plant. A safetyplan shall be defined during the design of the plant or during a major modification when the LNG storage capacityexceeds the threshold specified in the local regulation. If this value is not available, a threshold of 50 t isrecommended.The safety plan shall include an identification of risks and an appropriate appraisal of the consequences. It shallalso include the safety measures and principles of the actions performed by the operator for controlling risks foraccidents.Implementation of the safety plan shall be initiated as early as possible and be reviewed when unacceptable risksare identified during the design.A hazards and operability study (HAZOP or equivalent) shall be conducted to identify and eliminate or minimisehazards.Annex A illustrates the schematic description of the process related to an LNG satellite and fuelling plant. Thisdescription is simplified and it is not considered to be directly applicable for an actual project.5.2 Collection of data and informationInitially all available data and information shall be assembled. It should be related to: natural conditions: soil characteristics; meteorological conditions, to include at least atmospheric temperature and wind statistics, occurrence oflightning strikes, relative humidity, atmospheric stability; flooding risks; seismic activity; topography; vegetation for identification of fire risks; surrounding integration: surrounding infrastructure (e. g. industrial sites, built-up areas); access for possible LNG trucks; location of nearest fire services.When the available information is not sufficient enough to identify the possible risks or to define relevant measures,an additional survey of data may be performed.SIST EN 13645:2003



EN 13645:2001 (E)95.3 Threshold values5.3.1 Heat radiation from firesa) inside the plant:1) in the safety plan, it shall be determined if fire can damage pieces of equipment. The maximum thermalradiation flux until which a damage to the components may be acceptable shall be specified. Table 1 givesinformative maximum values excluding the solar flux, in case they are not already given in the localregulations.Table 1 — Thermal radiation fluxes excluding solar radiation inside the boundariesEquipment inside the plantMaximum thermal radiationfluxkW/m2Concrete surface storage vessels32Outer surfaces of pressure storage steel vessels and processfacilities15Control room, maintenance workshops, laboratories, warehouses,etc.8Administrative buildings5The radiation fluxes of Table 1 may be increased according to the duration of the fire. In any case, the maximumradiation flux levels acceptable for each main structure or equipment inside boundaries shall be confirmed by themanufacturer or using validated methods or curves defined in ENV 1991-2-2, ENV 1992-1-1, ENV 1992-1-2, ENV1993-1-1, ENV 1993-1-2 and ENV 1994-1-1 and ENV 1994-1-2.The time during which the radiation is experienced is a major factor in determining the consequences on people.The observed effects of thermal radiation are in summary: 1,5 kW/m2 will cause no discomfort for long exposure; 5 kW/m2 is sufficient to cause pain to people if unable to reach cover within 15 s; otherwise, blistering of theskin (second degree burns) is likely.The pieces of equipment can be either unprotected, or protected by means of water sprays, fireproofing screens orsimilar systems.For storage vessels, the permissible radiation flux shall be determined taking into consideration at least thefollowing factors: loss of mechanical strength of vessel; pressure build up within the vessel; the relief capacity of the safety valves; the temperature of the safety valve. It shall not reach the auto-ignition temperature of the flammable substancein the vessel.SIST EN 13645:2003



EN 13645:2001 (E)10Specific attention shall be given to aluminium-based vaporizers and piping which could be subjected to fire:b) outside the plant:1) Table 2 gives the recommended values for the maximum incident radiation flux excluding solar radiationbeyond a boundary in case it is not already defined in the local regulations.Table 2 — Thermal radiation fluxes excluding solar radiation beyond a boundaryArea adjacent to the concerned boundaryMaximum thermal radiation fluxkW/m2Isolated area: area only occasionally occupied by a reduced number ofpersons, e.g. farmland13Intermediate area: area which is neither isolated nor critical. This is thegeneral case5Critical area: place difficult or dangerous to evacuate quickly (e.g.sports stadium, play ground, .) or area where public circulationcannot be prohibited during emergencies.1.55.3.2 Heat radiation from flare or lightning of ventInside the plant boundaries, the designer shall make sure that the radiation flux excluding solar radiation cannotexceed 1,5 kW/m2 at buildings, vessels and other equipment for normal conditions and 5 kW/m2 for accidentalconditions.Outside the plant boundaries and for accidental conditions, the thermal radiation flux shall not exceed 5 kW/m2 inisolated areas, 3 kW/m2 in intermediate areas or 1,5 kW/m2 in critical areas. For normal condition, it shall be lessthan 3 kW/m2 in isolated areas and less than 1,5 kW/m2 in intermediate or critical areas.5.3.3 Ignition limit of natural gasThe flammable mixture range of natural gas in air is the value given in EN 1160:1996.5.4 Identification of risks5.4.1 Identification of risks of external originRisks arising from outside the plant can be listed on the basis of the aforementioned data. They may be caused by: LNG supply vehicles; heat radiation (fire); clouds of flammable, toxic or asphyxiating gas; impact of projectile; natural events (lightning, flooding, earthquakes .).5.4.2 Identification of risks of internal originPossible losses of containment of both liquid and gaseous natural gas shall be listed for all facilities includingsystems for loading or unloading vehicles. Leakage or spillage of natural gas may be defined by location, durationand flow rate.SIST EN 13645:2003



EN 13645:2001 (E)11The following causes of hazards which are not specific to LNG shall also be considered: LPG and heavier hydrocarbon storage; traffic within the plant; leakage of other hazardous substances, in particular flammable refrigerant; pressurised equipment (boilers.); rotating machinery; utilities, catalysts and chemicals (fuel oil, lubricating oils, methanol .); electrical equipment.5.5 Estimation of the consequences of a gas or LNG release5.5.1 GeneralThe consequences depend on the physical properties of LNG and other phenomena described in clause 5 ofEN 1160:1996. The informative annex B gives examples of consequences estimated for normal and accidentalconditions.5.5.2 Evaporation of LNGThe phenomena of instantaneous vaporisation (flash) due to depressurisation and heat transfer with the ground orwater for instance, shall be determined. Calculation may be carried out using appropriate validated models takingaccount of composition and flow rate of LNG, nature and temperature of ground and atmospheric conditions. Themodel may enable the determination of the time-dependent wetted area and the rate of evaporation.5.5.3 Atmospheric dispersion of LNG vapourCalculation of the atmospheric dispersion of the cloud resulting from evaporation of LNG may be carried out usingappropriate validated models. The model output are concentration contours and distance to the lower flammabilitylimit.5.5.4 Jet release of liquid natural gas or gaseous natural gasCalculation of atmospheric dispersion resulting from jet release shall be carried out using appropriate validatedmodels to determine at least the height or the distance reached by the jet and the concentration of gas at a givenpoint.5.5.5 Over pressure waveThe ignition of gas may create a deflagration generating an over pressure wave. Validated models shall be used tocalculate the over pressure field.This result shall then be used to appraise stresses on structures.5.5.6 RadiationCalculation of the radiation caused by ignition of the vapour from a pool or jet of LNG or release of gaseous naturalgas may be carried out using appropriate validated models. A vehicle fire may also be considered.The model enables the determination of the incident radiation at various distances and elevations.SIST EN 13645:2003



EN 13645:2001 (E)126 General safety measures6.1 Leaks and spillage protection6.1.1 Detection systemCorrect design, fabrication, construction and operation will minimize the quantity and frequency of leaks offlammable fluids. However, where leaks can occur and can escalate to a more serious incident, consideration shallbe given to the installation of fixed leak detection systems with executive action to stop the leak source, to isolaterelevant sections of plant and to shutdown sources of ignition in the vicinity.6.1.2 Piping and equipmentContraction/expansion phenomena due to temperature variations can induce material fatigue and create significantstresses in pipework and equipment leading to ruptures. To avoid this risk or to reduce the consequences, thefollowing arrangements should be taken: the number of flanges in pipe runs should be minimized. When it is possible, valves should be welded in line; the orientation of relief valve outlets shall be such as to minimize hazards. When a jet stream occurs, it shallnot reach nearby equipment or people; piping design shall take account of all operating conditions; systems shall be designed to avoid excessive operation of relief valves; pumps with high integrity seals or submerged motors shall be used for LNG; above ground vessels shall be located in the open; equipment containing flammable fluid should be located in the open, but this recommendation can be affectedby maintenance requirements or climatic conditions. In some circumstances, equipment may be installed inconfined areas, for instance, to ensure an early detection of small gas releases or to contain high pressurejets. If installed in a confined area, this area should be ventilated. The air renewal rate shall be determined byan appropriate study; routing of pipework through concrete walls shall allow free expansion of the pipework.Non-visible parts of pipework endangered to corrosion shall be subject to special protection.When under pressure, leaking valves or connections shall only be tightened using suitable tools and procedures.6.1.3 Impounding areasIf leaks of flammable liquids are considered to be a possible scenario, then the leaks should be confined by dykes.Flammable liquid flowing from a leak may be directed in open channels towards an impounding basin.The design of an impounding basin shall be such that flammable fluids do not enter the surface water drainagesystem.Consideration shall be given to the installation of leak detection devices and means to control the evaporation ratein the impounding basin. The basin may be partitioned to reduce vaporization of LNG and therefore gas emissioninto the atmosphere.When pipework is routed through the wall of an impounding basin, a suitable seal shall be provided.6.1.4 Protection against low temperatureIn the event of a leak, low temperature fluid can come into contact with metallic components which can fail due toembrittlement. Measures can be taken to prevent serious damage by suitable selection of materials of constructionor by embrittlement protection such as insulation.SIST EN 13645:2003



EN 13645:2001 (E)136.1.5 Isolation valvesIsolation valves shall be fitted as close as possible to the nozzles of process liquid outlets of pressure vesselscontaining flammable liquids such as hydrocarbon refrigerants and LNG. These isolation valves shall be remotelyclosed either by automatic emergency shutdown or by manual action.6.2 Overpressure protectionSafety devices shall be designed to prevent overpressure inclusive of fire engulfment. The gas discharged fromrelief valves of vessels and vaporizers should be safely discharged directly to the atmosphere or in cases wheredis
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